var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
var cookieParser = require('cookie-parser');
var session = require('express-session');
//使用中间件形式实现跨域访问
app.use("*", function (req, res, next) {
    //设置允许跨域的域名，*代表允许任意域名跨域
    res.header("Access-Control-Allow-Origin", "http://127.0.0.1:5500");
    //允许的header类型
    res.header("Access-Control-Allow-Headers", "content-type");
    //接收ajax请求手动提交的cookie信息
    res.header("Access-Control-Allow-Credentials", true);
    //跨域允许的请求方式 
    res.header("Access-Control-Allow-Methods", "DELETE,PUT,POST,GET,OPTIONS");
    if (req.method == 'OPTIONS')
      res.sendStatus(200); //让options尝试请求快速结束
    else
      next();
  });

  app.use(session({
      name: "sessionId",
      secret: 'blogzl',  // 用来对session id相关的cookie进行签名
      saveUninitialized: false,  // 是否自动保存未初始化的会话，建议false
      resave: false,  // 是否每次都重新保存会话，建议false
    }));

    app.use(function (req, res, next) {
      //后端打印
        console.log("req.url", req.url)
        console.log("Cookies: ", req.cookies);
        console.log("------------");
        if (req.url == "/users/login") { //如果是登录请求，直接通过验证
          next();
        }
        else { //表示非登录请求，需要验证session
          if (req.session.user) {
            next();  //session验证通过
          }
          else {  //session验证失败
            res.send({ succ: false, msg: "session无效，请重新登录" })
          }
        }
      });
app.use('/', indexRouter);
app.use('/users', usersRouter);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;
